This invention relates to a leg support. More particularly, this invention relates to a leg support for heavy industrial equipment, such as tables, refrigerators, ice makers, ranges, and other commercial kitchen equipment.
As is known, commercial restaurants employ equipment that is made of stainless steel or other non-corrosive materials. Typically, the equipment is relatively heavy and requires leg supports of considerable strength and bulk. In addition, since the equipment may be mounted on floors of uneven contour, the equipment requires leg supports which are adjustable in height in order to permit raising and lowering of the equipment to level the top surfaces of the equipment. The leg supports must also be made of materials that can be readily cleaned and that will not corrode over a period of time due to frequent cleanings with corrosive materials.
Typically, the leg supports have been made of relatively large metal elements in order to be able to carry the weight of the equipment while also satisfying the requirements for non-corrosion. However, these metal leg supports are relatively expensive to manufacture.
Attempts at making the leg supports of a plastic material to reduce the manufacturing cost have not been successful in producing a leg support which is capable of withstanding relatively heavy loads.
Accordingly, it is an object of this invention to provide an adjustable leg support of non-metallic materials which is capable of supporting heavy loads.
It is another object of the invention to provide a leg support with plastic load-bearing elements which are capable of bearing large loads.
It is another object of the invention to be able to provide a low-cost leg support of non-metallic elements which can carry relatively heavy loads.
It is another object of the invention to provide a non-corrosive adjustable leg support of high load bearing capacity and low cost.
Briefly, the invention is directed to a leg support which is comprised of a plastic housing having an upper support surface for receiving a load and a plastic foot threadably mounted in the housing and extending from one end of the housing. In accordance with the invention, the housing has an internal buttress thread and the foot has an external buttress thread threadably mounted in the internal buttress thread.
In accordance with the invention, the mating relationship between the two buttress threads is such that the internal thread of the plastic housing transfers the weight of a supported structure, e.g. a table, directly to the external thread on the plastic foot via the load receiving flank which is nearly perpendicular to the vertical axis of the plastic housing.
The lower load receiving flank of the internal thread of the housing is so nearly perpendicular to the thread axis that the radial component is reduced to a minimum. Preferably, the load receiving flank is disposed on an upwardly directed angle of from 1xc2x0 to 7xc2x0 relative to a horizontal plane.
The support surface on the housing is an annular surface and a metal bolt is mounted in the housing concentrically of the annular surface to extend from an opposite end of the housing for securement to a table leg or other supported structure.
The plastic housing is a longitudinally split housing formed of two longitudinally disposed pieces. The housing pieces are basically mirror images of each other except as described below. Each housing piece has a portion of the internal thread formed thereon and each has a recess for receiving one-half of the head of the bolt therein. In addition, a sleeve, for example, of metal, such as stainless steel, or other non-corrosive material is disposed over and coaxially of the housing for holding the two housing pieces together and for providing a smooth pleasing outward appearance.
When a load is transmitted onto the housing via the contact surface, the two housing pieces do not have a tendency to spread apart as would be the case with a conventional V thread form arrangement because of the not quite perpendicular nature of the internal thread of the housing on the not quite perpendicular flank of the external thread on the plastic foot.
The plastic housing is also provided with a plurality of circumferentially disposed reinforcing ribs which are disposed in facing relation to the sleeve. In addition, at least some of these ribs are of a greater outer diameter than the inner diameter of the sleeve so as to be deformed inwardly and downwardly between the sleeve and the housing when the sleeve is slid into place and to thereby frictionally hold the sleeve on the housing. In addition, the larger size ribs serve to adjust to sleeves of different inside diameter.
The plastic foot has a lower shank section of cylindrical shape which extends out of the plastic housing and is provided with a plurality of circumferentially disposed reinforcing ribs to deform and slidably receive a sleeve in friction fit manner. The external thread on the plastic foot is disposed on an upper section of the foot that is retained at all times within the plastic housing.
The sleeve disposed over the shank of the foot is of stainless steel or other non-corrosive material and is provided for aesthetic purposes. That is to say, the sleeve provides an aesthetic appearance without being a load-bearing member.
The plastic foot is hollow and has an end cap snap-fitted onto the bottom of the shank section in relatively rotatable manner in order to provide an enlarged bearing surface on a floor or other support surface. The cap has a greater outside diameter than the plastic foot and abut or be slightly spaced from the metal sleeve on the plastic foot.
The overall appearance of the leg support is provided by the two metal sleeves which are disposed about the plastic housing and plastic foot. In addition, the two sleeves present non-corrosive surfaces which can be easily cleaned by the usual cleaning solutions.